A new press image, released ahead of the fifth season of the smash period drama, is generating buzz after including a big blunder. The shot features the Earl of Grantham (Hugh Bonneville) and his daughter Lady Edith Crawley (Laura Carmichael) in front of a fireplace. While the props and set design are historically accurate to the grandeur of the early-Twentieth Century manor, a plastic water bottle is noticeably visible on the mantle.

Disposable bottles, like the one included in the pic, were not available until 1947, and it was not until the 1960s that plastic bottles were mass-produced by manufacturers. The fifth season of the show is set in 1924.

The cast teased the upcoming plot at the Television Critics Association in Beverly Hills, last month. "For every character, there are significant changes and plot points," Michelle Dockery — who plays Lady Mary — said. "But we wouldn’t want to spoil it for anyone." Dockery added to Us Weekly at a separate reception that she was a fan of the show's fashion. "This is part of the change for Mary in series five, because she's really embracing fashion."